Metachromatic leukodystrophy (MLD; Online Mendelian Inheritance in Man [OMIM] no. 250100) represents a rare, autosomal recessive disorder of lipid metabolism characterized by deficiency of the lysosomal enzyme arylsulfatase A (ARSA) due to mutations in the ARSA gene [1]. This evidence concerns the gene ARSA and metachromatic leukodystrophy.